Impact of Waste Iron Slag on Mechanical and Durability Properties of Concrete

Abstract

Waste management is of great concern in today’s world. Every year, an enormous amount of solid waste is generated from different industrial activities, especially the waste which is produced by iron industries in a particular form of slag. The major issue of emission of carbon dioxide (CO2) from cement industries is a serious problem for the earth's environment and the surrounding area. Thus, in this study, the waste iron slag obtained from nearby iron industries was used as a partial substitute for cement. The cement was replaced with iron slag (IS) at the substitution levels of 7.5%, 15%, 22.5%, 30% and 37.5% by weight of cement. The doses of superplasticizer for every mix were taken based on the essential workability requirements for the reinforcedconcrete work. Performance of control and blended mixes was evaluated by workability evaluation, compressive strength test, flexural strength test, water permeability test, water absorption evaluation, rapid chloride penetration test (RCPT) and carbonation test. Scanning electron microscopy (SEM), X-ray diffraction (XRD) technique and thermogravimetric analysis (TGA) technique were used to assess the micro-structural changes and to evaluate the chemistry of the blended mixes. The results obtained from this study were encouraging in terms of compressive and flexural strengths. The maximum compressive and flexural strengths were recorded at a 22.5% replacement level of slag. The results obtained at 30% replacement were also better compared to the control mix. The resistance of slag-made concrete mixes against adverse conditions; i.e., CO2 penetration, chloride penetration and water penetration was far better than that of conventional ones. The results obtained from TGA indicated that the productivity of calcium silicate gel of slag concrete is better than that of control concrete. KEYWORDS: Concrete, Slag, Carbonization, RCPT, XRD, TGA, SEM.

Effective Use of Waste Plastic As Sand in Metakaolin/Brick-Powder Geopolymer Concrete

“…Recently, global warming, environmental pollution and large-scale consumption of natural resources have become major crises threatening the world and life on earth (Wang et al, 2021). Having been associated with rapid population growth and urbanization, the vast amount of concrete produced as the key building material of most infrastructures and construction applications has caused significant environmental impacts across the globe (Jain et al, 2023;Rama and Shanthi, 2023). The main eco-drawbacks of concrete come from the energy intensive nature of manufacturing ordinary Portland cement (OPC), which is the main binder in concrete, the volume of raw materials consumed in the process and the contribution of 7-8% of the overall worldwide carbon dioxide (CO2) emissions (Ahmed, 2021).…”